Born in Vermont in 1837 but raised in the Empire State, John Newton Chamberlin was a teacher and farmer in Cayuga County, New York when he decided in September 1861 to enlist in the 75th New York Volunteer Infantry regiment. After six weeks of training, the unit left New York City harbor on the steamer Baltic, bound for Florida. It is at this moment that Chamberlin's correspondence begins, his wartime letters and diary edited by descendant John Bisbee and published in Captaining the Corps d'Afrique.

Arriving at Santa Rosa Island, the 75th and their Union comrades at Fort Pickens faced off the Confederates across the water at Pensacola, before the enemy evacuated the area in early 1862 (their presence in the interior required after a series of military disasters in Tennessee). Even at this very early stage of the war, Chamberlin's letters home advocated emancipation as a war measure.

In September 1862, the 75th was transferred to New Orleans, where Chamberlin noted the organization of black troops in the city. Sick with mumps, he missed the 1863 Bayou Teche operation, so he must have gleaned information from comrades and the rest of the army grapevine for his accounts of the battles fought at Bisland and Irish Bend. While expressing distaste for Ben Butler's rumored corruption while in charge of the department, Chamberlin's letters direct even more disapproval toward Nathaniel Banks's kid glove treatment (in his view) of area merchants and planters who professed loyalty to the federal government. The recovering Chamberlin finally rejoined his regiment in the field at Port Hudson, with the siege operation phase of the campaign already underway.

In July 1863, after the fall of Port Hudson, Chamberlin was approached by Major George D. Robinson to join the newly organizing 3rd Regiment of Engineers, Corps d'Afrique as the captain of Company E. He readily accepted. Curiously, Chamberlin mentions that he preferred the transfer to a black unit over staying in the 75th, as he had witnessed there the intense jealousy and lack of appreciation felt among those in the ranks for new officers promoted from within. Whereas some officers of black units undoubtedly viewed the position primarily as a fast-track opportunity for gaining shoulder straps and escaping the drudgery of the ranks, it's clear from his own writings that Chamberlin possessed a genuine, if highly paternalistic, enthusiasm for emancipation and the bringing of black soldiers into the fight.

The men of the 3rd Engineers were trained for road construction, bridging operations, clearing river obstructions, building earthwork defenses, as well as other duties typical of Civil War pioneer detachments, and Chamberlin proved to be an able chronicler of their wartime service. During its first operation, the regiment acted in the capacity of pontonniers, accompanying the September 1863 Texas invasion that was famously thwarted by a tiny force of Confederate defenders at Sabine Pass. Other tasks performed that year included clearing sunken hulks from Vermilion Bayou and constructing fortifications at Berwick City.

In spring 1864, the 3rd Engineers left Berwick City and joined the ill-fated Red River Campaign. They played important roles in a number of key events, including the bridging of the Cane River and the dam construction at Alexandria, and these moments are recounted in Chamberlin's diary and letters. He also offers a vivid picture of the destruction meted out to the town of Alexandria when the Union army and navy exited the region in defeat.

After a period of further training, the engineers were next sent to Dauphin Island off Mobile Bay for repair work on captured Fort Gaines. From there, they returned to Florida for a time. Chamberlin describes in his diary the December 1864 engagement at Pine Barren Creek, one of the few pitched battles that the engineer unit participated in during its service. In closing out the war, Chamberlin and his men constructed batteries and redoubts during the 1865 siege operation that finally seized Mobile.

In addition to containing descriptive accounts of military events, Chamberlin's letters also discuss the important political and social issues of the day in a thoughtful manner. They convey a great deal of support for the temperance movement, with drunkenness one of several reasons cited by their author for wanting to leave the 75th New York. Like many Union soldiers, Chamberlin shared with family and friends his view of the home front "Copperhead" movement as a stab in the back to the fighting men in the field. For Chamberlin, Lincoln's re-election in 1864 was essential to finishing the war. While assigning much of the blame for the conflict on wealthy slaveholders, Chamberlin's letters do view the institution of slavery itself as a national sin, with both sections shouldering blame for the perpetuation of slavery and for the secession crisis. He was also deeply conflicted over the war's destructiveness, expressing more than the typical degree of soldier empathy for the sufferings of the South's civilian population. While Chamberlin did not consider blacks his social or intellectual equal, he actively worked toward their betterment by creating company schools, using his own personal funds to purchase supplies. In his private letters to family and friends he also communicated considerable worry over what would happen to his men in the post-war South, especially after seeing how the Johnson administration was handling civil rights for freedmen.

In the process of editing the material for publication, John Bisbee conducted more than adequate research of his own, with his supporting narrative and notes offering useful background and context for Chamberlin's writings. While the volume doesn't examine Chamberlin's pre-war life to any great degree, and epilogue does discuss his sad fate. Though able to work and raise a family, chronic ill health (presumably the result of lingering complications of the tropical disease, or diseases, he contracted during the war) and severe episodes of depression plagued Chamberlin, ultimately leading him to take his own life in 1880.

The publication of Civil War writings of white officers that led black units is an uncommon event, made even more rare with Captaining the Corps d'Afrique by the specialized nature of the unit involved. John Newton Chamberlin's detailed diary and letters comprise perhaps a unique firsthand record of the service of black engineers in the western and Trans-Mississippi theaters, with the eloquence of the writer's political and social commentary an added benefit to the modern reader. Well read Civil War students are always looking for something fresh and new, and this volume certainly possesses those sought after qualities.